About half of all industrial distillation columns in process plants use distillation trays. The function of these separation devices is to promote contact between liquid and vapor phases so mass transfer between the two phases can occur.

The three most common types of distillation trays are sieve trays, valve cap trays, and bubble cap trays. Sieve trays are the cheapest and simplest type of tray, consisting of metal plates with holes in them. Vapor passes straight upward through the liquid on the plate.

Valve cap trays feature holes covered by liftable caps. Vapor flows lift the caps, thereby creating a flow area for vapor to pass through horizontally into the liquid. This design provides better mixing than sieve trays.

Bubble cap trays feature risers over each hole with a cap that covers the riser. A space between the cap and riser allows vapor to flow through the riser before being directed downward by the cap. Vapor is discharged through slots in the cap and bubbles through the liquid on the tray.

Bayport Technical's Distillation Trays Model - Acrylic (135-TRAY2) exhibits three different types of distillation trays similar to those employed in the 132-DTT5, allowing for a clear, close-up view of the individual trays without any equipment obstructing the view. This is a static model meant for educational purposes.

The model includes the following: valve cap tray, bubble cap tray, and sieve tray.